Technological ONION

1. Technological ONION • Sources: Patricia Setser • Modified: Margaret Lion Computer Systems – Hardware

2. Relationship of OS to hardware and software ONION ANALOGY

3. Computer Hardware • Hardware is the computer and any equipment connected to it • Hardware devices are the physical components of the computer • Items such as the monitor, keyboard, mouse, and printer are also known as peripherals because they attach to the computer • Something you can touch.

4. Computer Hardware - Functions • Information processing cycle of a computer • Input – Computer gathers data or allows a user to add data • Processing – Data is converted into information • Output – Data or information is retrieved from the computer • Storage – Data or information is stored for future use

5. Types of Computers • Supercomputers – • Large, powerful computers devoted to specialized tasks • Fastest and most expensive of all computers • Perform sophisticated mathematical calculations, track weather patterns, monitor satellites, and perform other complex, dedicated tasks • Cost: $1M - $30M + • Purpose: Numerically intensive scientific applications, research

6. Types of Computers • Mainframe computers – • Large computers often found in businesses and colleges, where thousands of people use the computer to process data • They Multitask, as they can perform more than one task at the same time This capability is one of the primary ways mainframes differ from supercomputers • Cost: $500K - $10M + • Purpose: Large businesses

7. Types of Computers • Microcomputers – • Are the smallest of the categories of computers and the one that most people typically use • Range in size from servers that have a storage capability of minicomputers (and small mainframes) to handheld devices that fit in your pocket • Cost: $400 - $5K • Purpose: Personal, Put on LANs, Small Business

8. Types of Microcomputers • Microcomputers – smallest type of computers • Desktop computers sit on your desktop, floor, table, or other flat surface and have a detachable keyboard, mouse, monitor and other pieces of equipment • Notebook computers, also called laptops, which are mobile • Tablet computers, similar to notebooks but screen can be written on with a special pen called a stylus • Smartphones offer more computer capabilities then the PDA.

9. Components - System Unit • System Unit • If you remove the cover from the system unit, you find several key components inside

10. Components - System Unit • One of the most essential components is the microprocessor chip, also known as the central processing unit (CPU) • The CPU is located on the motherboard, a large printed circuit board to which all the other circuit boards in the computer are connected

11. Components - Central Processing Unit • System Unit • The CPU is the brain of the computer and is responsible for controlling all the commands and tasks the computer performs • Two main parts – the control unit and the arithmetic logic unit (ALU) • The control unit is responsible for obtaining instructions from the computer’s memory, and then interprets and executes them

12. Basic Computer Hardware - Functions

13. Components - Central Processing Unit --- MOTHERBOARD • Motherboard/system board • Main computer circuit board; connects all components

14. Hardware Devices and Their Uses Memory is another critical computer component found within the system unit - Two types of memory: ROM and RAM • RAM - Temporary holding area where data is stored – RAM means Random Access Memory • RAM acts as the computer’s short-term memory and stores data temporarily as it is being processed • RAM is considered to be volatile because this memory is erased when the computer is turned off • ROM, orRead Only Memory, is prerecorded on a chip • Information on a ROM chip can’t be changed, removed, or rewritten • Nonvolatile memory -- it retains its contents even if the computer is turned off • ROM is used to store critical information such as the program used to start up, or boot, the computer

15. Components - Data Storage • Storage Devices – Memory Types • Store data and information used by or created with the computer • This storage is permanent memory, because data saved to a storage device remains there until the user deletes or overwrites it • Volatile memory is any memory that would be lost once the computer was shut off.

16. Components - Data Storage • Storage Devices • Flash memory is a popular form of storage • Used in PDAs, digital cameras, and MP3 players • It is a mechanical drive • Hard disk drive – A hard disk drive is the computer’s largest internal storage device - Usually measured in gigabytes (GB)

17. Components - Data Storage • Storage for data is given in bytes • 1 Kilobyte (KB) = 1,024 bytes • 1 Megabyte (MB) = 1,048,576 bytes or1,024 KB • 1 Gigabyte (GB)= Little over 1 billion bytes or 1,024 MB • 1 Terabyte (TB) = 1,024 GB Source: http://www.kb.iu.edu/data/ackw.html And https://ittraining.iu.edu/workshops/winba/winba.pdf, page 12

18. Components - Input Devices The two most common: Keyboard – Contains groups of keys used in different ways to input data: for example, the typing keypad is used to enter text and other data. The numeric keypad is used to enter numbers and perform calculations. For more information visit Using your keyboard. Mouse – Small hand-sized unit that acts as a pointing device. For more information visit Using your mouse.

19. Components - Output Devices • Hardware used to get data and information from the computer into an understandable format. • Monitors (aka computer screens) – Display data, text, and graphics. • Printers – Produce paper printouts of data and information. Also can be input devices if they include scanning, faxing, and copying capabilities.

20. Further Study • For more information visit the Microsoft site Parts of a computer and Introduction to computers.